Blower wheel construction



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5, 153 c. H. PLACE 296379489 BLOWER WHEEL CONSTRUCTION Filed Feb. l9, 1949 2 SHEETS-SHEET l Hes.

. INVENTOR, GHHRLES I. Pm c5 59 53 c. 11. PLACE 37 489 BLOWER WHEEL CONSTRUCTION Filed Feb. 19, 19 49 2 SHEETS-SHEET 2 INVENTOR; CHARLES 1. PLACE A TTORNEY Patented May 5, 1 953 UNITED STATES PATENT OFFICE BLOWER WHEEL CONSTRUCTION Charles I. Place, Norfolk, Conn.

Application February 19, 1949, Serial No. 77,310

8 Claims.

This invention relates in general to fan or blower wheels of multi-blade type, and has particular reference to improvements in respect to the construction and manner of assembly of such wheels. The principal object of the present invention is to afford a multi-blade fan wheel of improved and simplified construction, wherein the wheel parts are so designed that they may be readily and economically formed from sheet metal, plastic or other suitable materials, and further, wherein the parts are adapted for easy and quick assembly with the aid of a minimum of assembling tools, and without requiring more than ordinary skill to effect assembly. Another object is to provide a fan wheel of greatly simplified yet sturdy construction, which may be shipped or transported in disassembled or so-called knock-down condition to efiect savings in packaging costs and shipping space, and which thereafter may be readily assembled in the field.

A further object expressed more particularly with regard to present structural novelty, is to provide a fan wheel of multi-blade, centrifugal displacement type, comprising relatively spaced blade positioning members each having an annular series of slots, slotted blades received through the slots of the positioning members and interlocked with the members through the blade slots, and a securing element carried by one of the positioning members and engaging the blades in a manner to retain the blades and positioning members firmly in interlocked assembly.

Yet another object resides in the provision of a centrifugal displacement fan wheel of the improved character indicated, including wheel bracing means and embodyin in addition to centrifugal blades, fan blades of propeller or axial displacement type. The foregoing and other objects and advantages of the present invention will appear readily from the following description of presently preferred embodiments thereof, as exemplified in the accompanying drawing, wherein:

Fig. 1 is a view in sectional elevation axially of a centrifugal displacement fan wheel of single intake form, constructed in accordance with the present invention; 1 Fig. 2 is an assembly view in front elevation of the fan wheel, shown with portions thereof broken away in order to disclose structural features of the fan assembly; .1. Fig. 3 illustrates in axial sectional elevation, a modification of the fan wheel to afforda doubleintake form thereof;

- Fig. .4 is an assembly view in front elevation, of

another embodiment of the present invention, providing a single-intake centrifugal displacement fan wheel having wheel bracing elements and blades of propeller or axial displacement form, the view showing parts broken away to reveal structural details;

Fig. 5 is a fragmentary side view of the embodiment of Fig. 4;

Fig. 6 is a view in axial sectional elevation, of

the embodiment according to Fig. 4, and

Fig. 7 is an enlarged view in perspective, of one of the combined brace and propeller blade elements of the assembly.

Referring first to the embodiment of Figs. 1 and 2, the presently improved and simplified centrifugal fan wheel there shown, includes an annular series of equally spaced blades 10 forming an open-interior wheel body, an annular or ringform end plate I I the central opening I 2 of which defines the intake opening of the wheel, and a back plate M of disc-form. As will appear presently, the plates II and I4 constitute the blade positioning and supporting elements of the assembly. Completing the essential elements of the present wheel is a disc member l5 which serves in a manner to be described, to lock the wheel parts in assembly. By present preference, member l5 carries a hub is for mounting the wheel on the shaft of a drive motor (not shown), the hub having a shouldered projection l8 at one end seated through a central opening [9 in member l5, with the free end portion of the projection turned or peened-over against the member, as shown, to eifect a rigid clamped assembly of the hub and member. A set-screw ll in the hub serves to eifect a shaft-hub connection.

The blades It) preferably are of curved form in section as appears in Fig. 2, although they may be flat or straight blades if desired. Each blade is formed to provide a slot 28 (Fig. 1) near one end and a similar slot 2! near the opposite end, with the slots open to the outer longitudinal blade margin 22. Annular end plate I I has equally spaced slots 23 around its inner margin 24 and open to the margin, the number of slots being equal to the number of blades H3 and each slot being curved in conformity with blade curvature. Back plate It is provided with an annular series of closed slots 26 inwardly of its periphery 21, the slots being equally spaced and corresponding in number to the number of blades It, with each slot curved in conformity with blade curvature. Further, the length of each slot in its curved extent, is only slightly greater than the curved dimension of the blade between its outer margin 22 and inner margin 28, in order to permit blade extension through the slot in the assembly operation.

Each blade is interlocked with the end ring plate ll through the positioning of a blade end through a plate slot 23 with the blade slot 28 embracing the plate beyond slot 23, and with the inner end 30 of blade slot 28 in contact with the inner end 3! of the plate slot 23. Similarly, each blade is interlocked with the back plate i4 through the positioning of the opposite blade end through a closed slot 26 of the plate with the blade slot 2| at such end, embracing the back plate beyond slot 26, and with the inner end 32 of blade slot 21 in contact with the outer end 34 of plate slot 25. As so positioned, the outer longitudinal margins 22 of the blades are substantially flush with the outer circular peripheries of the end and back plates. The parts as thus far described, are held firmly in interlocked assembly, by the disc member i5 which as will be observed in the drawing, is positioned fiat against one side of back plate is with hub iii extended through an opening 35 in the back plate. The diameter of member I5 is such that when positioned as aforesaid, the circular periphery 36 of the member will be in edge-abutment with the inner margins 28 of all the blades i0, thus securing the blades and plate members in interlocked assembly. Member 15 is retained in place by suitable rivets 38 through the member and back plate M. In practice, rivet holes may be provided in the back plate and in the member l5 when these elements are formed, and these holes brought into alignment coincidentally with the positioning of member 15 to lock the parts in assembly, whereupon rivets 38 may be inserted and secured. Alternatively, the back plate and secured together in any other desired manner, i

as by spot-welding or the like, or in order to permit ready dis-assembly of the wheel, the disc member l5 may be attached to the back plate by removable screws or bolts.

The several parts of the presently improved fan wheel may be easily and inexpensively formed from sheet metal or other suitable sheet material, by relatively simple cutting or stamping operations, or certain or all of the parts may be molded or die-cast plastic material, with the blades given a straight or curved shape as desired, in the molding or casting process. In the instance of blade stampings from sheet material, the blades may be given the desired curvature by any well known rolling or form-pressing process.

The parts when formed, are adapted for quick and easy assembly by any one of ordinary skill, using but a few simple tools. For example, the end ring II and back plate l4 may be held by suitable clamps or other means, in horizontal positions such that one is in overlying registry with the other and vertically spaced according to the longitudinal spacing of the blade slots 26 and 2|. Whereupon the blades H] are manually positioned one at a time, in spanning relation to the plates and such as to seat one slotted end of the blade in a back plate slot, and coincidentally therewith, the opposite slotted end of the blade in a slot of the ring plate. The blades then are urged outwardly toward the plate pe ripheries until the ends of the blade slots engage ends of the plate slots, as hereinbefore described. Thereafter, disc member I5 is applied against the back plate with its periphery in edge-abutment with the inner margins 28 of the blades,

thereby effectively relating the parts in firm interlocked assembly. Riveting of the member I5 to ie back plate It through rivet application by a simple rivet-applying tool, completes the assembly with the exception of bracing elements hereinafter to be described, which in certain fan applications, may be omitted. Since the disc member i5 is provided with the hub l6 secured to it, the wheel as thus assembled, is now ready to be mounted on a wheel drive shaft, as the rotor shaft of a drive motor or the like.

It will be appreciated now that the fan wheel according to the embodiment hereinabove described, is of greatly simplified construction, presenting pre formed part adapted for easy and quick assembly either at the point of fan production or in the field. Moreover, an important feature of the wheel structure is the retention of the blades and blade positioning plates in relatively interlocked assembly, solely by a single element, as the disc member [5, acting through the blades in the manner described.

Where the fan wheel in use, is subjected to rapid acceleration from stand-still, or hightorque starting, cocking stresses normally will be set up in the wheel structure. These and other stresses incident to such starting, may resuit in cooking or relative angular displacement diiierent parts of the wheel. Consequently, it is d .irabie to strengthen the wheel against such ;es, and provision to that end is here made. Fast, it is to be noted that where the starting torque imposed on the wheel is not particularly excessive, wheel bracing inherent in the blades because of their curved configuration, may be sufficient to counteract cocking stresses. Moreover, the bracing function of the blades, whether curved or fiat blades are embodied in the structure, may be considerably increased by disposing the blades such that each is at an appreciable angle to a radius of the wheel, within the limits set by aerodynamic eificiency. Thus in the embodiment of Figs. 1 and 2 herein, the curved lades it are set such that the chord line of each is at an appreciable angle to a wheel radius through the inner margin 28 of the blade.

However, in order to assure adequate bracing of the wheel irrespective of or in addition to the inherent bracing efiect of the blades, suitable struts or bracing elements 40 may be incorporated in the wheel structure. Preferably three such struts are used, each strut having an eye 4| at one end secured as by a rivet 42 to the end ring i i. Each strut is extended at an angle depthwise in the Wheel body interior, to a point of the back plate I4 relatively near the hub [6, where it is secured to the plate through an eye 44 on the strut, preferably riveted to the plate as shown.

With further reference to the embodiment of Figs. 1 and 2, while the disc member [5 having hub, It thereon, is located against the outer side of back plate It with the hub extending through the back plate and into the wheel interior, it will be appreciated that disc 15 may be inserted from the wheel inlet side to a position against the inner side of the back plate, with the hub l5 extended through the back plate and outwardly therefrom. Moreover, it will be appreciated from the character of the parts and manner of assembly thereof as hereinabove described, that the end ring ll, back plate 14 and blades l0 may be selectively related for assembly to present a fan Wheel operative in either clockwise or counterclockwise rotation. For example, the parts related as shown in Figs. 1 and 2 for clockwise rotation of the wheel (Fig. 2) may be assembled for counterclockwise Wheel rotation merely by inverting the end ring and back plate such that the curved slots thereof are directed oppositely to the direction appearing in Fig. 2, and then applying the blades in the manner of assembly as before described.

Fig. 3 illustrates a double-entry or double-intake form of the fan Wheel of Fig. 1. The parts are formed exactly as in the first case, with the exception that the blades 45 are of increased length and each has end slots 46 and 48, and a slot 49 intermediate the blade ends. An end ring 50 is at one end of the wheel, while a like end ring 52 is at the opposite wheel end, and a plate member 53 corresponding to back plate 14, is interlocked with the central portions of the blades through the blade slots 49. Associated with the centerplate 53 is the lock plate or disc 54 having the wheel shaft-mounting hub 56 thereon. These parts are assembled substantially in the manner described for the embodiment of Fig. 1, and hence no further description thereof is thought to be necessary here.

Because of the increased axial extent of the double-entry wheel, provision is here made for strengthening the assembly. As appears in Fig. 3, a disc-like plate element 51 is located against the center plate 53 on the side thereof opposite to the side engaged by the lock disc 55, and has its peripheral margin 58 in edge-abutment with the blades t5. Strengthening plate 57 is centrally apertured to accommodate hub 56, and may be held in assembly by extension of the rivets 60 attaching lock plate 54 to plate 53, through the plate 51 as shown. Additionally, struts 6| between the end ring 50 and plate 51, and struts 62 between the end ring 52 and lock plate 54, may be included in the assembly to counteract torsional and other stresses in wheel starting and running operation.

A modified embodiment of the invention is shown by Figs. 4 to 7. As therein illustrated, the modified fan includes a plurality of straight or fiat blades 70 arranged in an annular series, each blade having a slot il in one end and a slot 72 in the opposite blade end, with both slots open to the outer longitudinal margin 74 of the blade. An annular plate member or end ring 15 the central opening 16 of which defines the intake opening of the wheel assembly, is provided with an annular series of radial slots 78 open to the inner circular margin 19 of the ring. Corresponding ends of the blades are received through the ring slots 18 and are interfitted with the ring in the manner described for the assembly of Fig. 1. At the opposite end of the Wheel is a disc-like back plate member 80 which is formed to have an annular series of closed slots 82, these slots receiving the opposite corresponding ends of blades 10 with the blade ends interfitting the plate through blade slots 12, as in the manner of the assembly of Fig. 1.

Departing from the first described embodiment of Fig. 1, each of the ring slots 18 and plate slots 82 has a width which is greater than the thickness of the blade end received therein. The greater width of the slots 78 and 82 is here afforded to accommodate in addition to the blade ends, the slotted ends 83 and 84 of wheel reinforcing struts or braces 86. Each strut is of plate-form corresponding somewhat to the blades Ill, and is arranged to extend diagonally in the axial direction of the wheel, between one end of one blade Ill and the opposite end of the next adjacent blade 10, as clearly shown in Figs. 5 and 6 of the drawing. The slotted end 83 of the strut is received in a ring slot 18 such that the strut end and the blade end in the same slot, are closely confined in the slot and interlocked with the ring. Similarly, the slotted end 84 of the strut is received in a plate slot 82, with the strut end and the blade end in the same slot, closely confined therein and interlocked with the plate. Suitably secured to the plate as by the rivets 87, is a lock disc or plate element 88 which has its circular periphery in edge-abutment with the inner margins 90 of the blades 10 and the inner margins 9| of the strut ends 84. The parts thus are firmly retained in interlocked assembly. For wheel shaft-mounting, disc 88 carries a hub 92 which may be secured thereto in the manner described for the hub IS in the fan of Fig. 1. Hence, the modified structure as thus far described, presents a centrifugal blower wheel generally similar in parts and manner of assembly thereof, to the wheel of Fig. 1, but differin importantly from the latter in the character and arrangement of the struts or brace elements 86 here employed to strengthen the wheel against the effects of torsional and other stresses set up in wheel starting and running operations.

A further important and distinguishing feature of the modified wheel assembly resides in the propeller blades 94 disposed radially outwardly of the blades '50, which propeller blades serve to increase the displacement capacity of the present wheel. By reason of the assembly arrangement of the struts 86, these struts may be employed most conveniently, to support the propeller blades B l. To this end the blades may be attached to the struts, or by preference as shown in Figs. 4 to '7, each blade 94 is formed as an integral extension of a strut. While all of the struts in the embodiment of Fig. 4 have integral propeller blade extensions, it will be appreciated that the fan Wheel may incorporate a lesser number of propeller blades, as by employing struts devoid of the blade extensions, in an alternate relation with struts provided with such blade extensions. Thus the presently modified assembly may be characterized as a combined centrifugal and propeller fan wherein the air discharge from the centrifugal fan portion supplies in part, the air intake of the propeller fan portion.

Although the wheel blades H! are shown in the present example as being of flat or straight form, blades of any desired curvature may be used instead, in which case the blade-receiving slots in the ring member 75 and back plate 88 will be of curved extent corresponding to the particular curvature of the blades. Additionally, the struts will have to be modified at least in respect to the slotted ends 83 and 84 thereof, such that the latter are curved correspondingly to blade curvature, in order that the strut ends may be received in the curved slots of the plate elements "l5 and 89. With regard to the shape of the propeller blades M, it will be appreciated that these blades may be flat or curved as desired.

From the foregoing description of the embodiments as illustrated, it will be new appreciated that in each case, the parts are provided as preformed elements adapted for ready assembly in a manner easily effected by anyone of ordinary in knocked-down condition, thus permitting 7 marked savings in packaging and shipping costs.

Having now described and illustrated several presently preferred embodiments of the present invention, it is to be understood that such description and illustrations are to be considered as exemplary only, since various modifications in the parts and relative assembly thereof, may be made without departing from the spirit and scope of the invention as defined by the appended claims.

I claim:

1. A displacement device for fluids such as air, comprising displacement blades arranged in an annular series, a ring plate engaging corresponding ends of the blades, a support member era-- gaging the opposite correspondin ends of said blades, hub means on said support member for shaft-mounting the device, bracing elements between the ring plate and support member, each of said bracing elements extending substantially diagonally between an adjacent pair of said displacement blades, and propeller blades carried by at least certain of said bracing elements.

2. A displacement device for fluids such as air, comprising centrifugal displacement blades arranged in an annular series, a ring plate engaging corresponding of said blades, a disc member having an annular seri s of slots therein receiving said blades, a member on said disc member and engaging the inner edges of said blades to retain the blades and disc member in assembly, bracing elements between said ring plate and disc member with an end oi each element received in one of the slots in the disc member, and propeller blades carried by at least certain of said bracing elements.

3. A displacement device for fluids such as air, comprising a ring plate having slots substantially equally spaced around the plate, a disc member having slots substantially equally spaced circularly of the disc adjacent the peripheral margin thereof, a plurality of centrifugal displacement blades arranged between the plate and disc with portions of the blades received in the plate and disc slots, means on said disc member engaging inner edges of said blades to retain the blades in the disc slots, bracing elements having end portions received in the slots of the plate and disc, and propeller blades carried by said bracing elements.

A displacement device of the character described, comprising a plurality of centrifugal displacement blades arranged in an annular series, each blade having open slots in one longitudinal margin thereof, a ring plate having open slots equally spaced about the inner periphery of the plate, said plate receiving corresponding end portions of said blades with one slot of each blade embracing said plate, a disc member having an annular series of closed slots therein, said blades being received through said disc slots with a second slot of each blade embracing the disc member, bracing elements between the ring plate and disc member and having the ends thereof in said slots of the plate and disc member, a member on said disc member having a circular peripheral margin in abutment with edge portions of said blades and bracing elements to retain the blades and bracing elements in assembly with the disc member, and propeller blades carried by said bracing elements.

5. A displacement device for fluids such as air, comprising displacement blades arranged in an annular series, a ring plate engaging corresponding ends of the blades, a support member en- 8 gaging the opposite corresponding ends oi. said blades, and bracing elements between the ring plate and support member, each of said bracing elements extending substantially diagonally between an adjacent pair of said displacement blades.

6. A displacement device for fluids such as air, comprising displacement blades arranged in an annular series, a ring plate having slots substantially equally spaced about the plate, the slots engaging and receiving corresponding ends of the blades, a support member engaging the opposite corresponding ends of said blades, hub means on said support member for shaft-mounting the device, bracing elements between the ring plate and support member, each of said bracing elements extending substantially diagonally between an adjacent pair of said displacement blades with an end. of each element received in one of the slots in the ring plate, and propeller blades carried by at least certain of said bracing elements.

7. A displacement device for fluids such as air, comprising centrifugal displacement blades arranged in an annular series, a ring plate engaging corresponding ends of said blades, a disc member having an annular series of slots therein receiving said blades, a member on said disc member and engaging the inner edges of said blades to retain the blades and disc member in assembly, bracing elements between said ring plate and disc member, each of said elements being extended substantially diagonally between an adjacent pair of said displacement blades with an end of each element received in one of the slots in the disc member, and propeller blades carried by at least certain of said bracing elements.

8. A displacement device for fluids such as air, comprising a ring plate having slots substantially equally spaced around the plate, a disc member having slots substantially equally spaced circularly of the disc adjacent the peripheral margin thereof, a plurality of centrifugal displacement blades arranged between the plate and disc, each blade having an open slot in each end portion thereof, corresponding end portions of the blades being received in the plate slots with the blade slots at said end portions embracing the ring plate, the opposite corresponding end portions of said blades being received in the disc slots with the blade slots at said end portions embracing the disc, means on said disc member engaging inner edges of said blades to retain the blades in the disc slots, bracing elements having end portions received in the slots of the plate and disc, and propeller blades carried by said bracing elements.

CHARLES I. PLACE.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,020,771 Minor Mar. 19, 1912 1,131,555 Ritter Mar. 9, 1915 1,378,008 Candee May 17, 1921 1,700,017 Bender Jan. 22, 1929 2,350,739 Ferre June 6, 1944 2,357,618 Swift Sept. 5, 1944 2,392,113 Anderson Jan. 1, 1946 2,443,411 Wolfe June 15, 1948 FOREIGN PATENTS Number Country Date 225,640 Great Britain Dec. 11, 1924 

